2.1.1. Conventional MMS methods
A few researchers have worked to develop an effective MMSmodel. In 1973, a mining method classification system had demon-strated by Boshkov and Wright [10] which recognised as the one offirst quantitative approaches. The first quantitative ranking systemfor MMS analysis presented by Nicholas [11], but the proposed system had a critical defect in that all criteria were considered equallyimportant. Nicholas [9] modified the initial MMS method by adopt-ing weighting factors for the criteria, but this modification receivednegative reviews because of the narrow ranges of score disturbsthe optimum selection. Later, Miller-Tait et al. [12] reformed theNicholas method by extending the maximum and minimum sco-ring domain.
2.1.2. MMS using soft computing technologies
Although conventional mining method classifications and quan-titative and qualitative ranking systems are very convenient forMMS processes, the possibility of subjective effects by decisionmakers remains. Thus, with the intention of solving this complexproblem, different SC approaches have been designed by variousresearchers.